Railway signaling system.



No. 839,525. I PATENTED DEC. 25, 1906. L. H. THULLEN.

RAILWAY SIGNALING SYSTEM.

APPLICATION FILED JANA, 1904.

6 SHEETS'SHEET 1.

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PATENTED DEC. 25, 1906.

L. H. THULLEN. RAILWAY SIGNALING SYSTEM.

APPLICATION FILED JAN.4,1904.

6 SHEETS-SHEET 2 Iwaziar L-HJZILZZFIL No. 839,525. PATENTBD DEC. 25, 1906. L. H. THULLBN. RAILWAY SIGNALING SYSTEM.

APPLICATION FILED JANA, 1904.

B SHEBTS-SHEET 3.

.Zzwnlaz 11.1% FM No. 839,525. PATENTED DEC. 25, 1906.

L. H. THULLBN. RAILWAY SIGNALING SYSTEM.

APPLICATION FILED JANA, 1904.

' e SHEETS-SHEET 4.

'FTETKQ-u 110mm) Lubf- T N0. 839,525. PATENTED DEC. 25, 1906.

L. H. THULLBN. RAILWAY SIGNALING SYSTEM.

APPLICATION FILED JANA, 1904.

6 SHEETS-SHEET 5.

INVENTOR 27.1% Thu Zlen,

No. 889,525. PATENTED DEC. 25, 1906. L. H. THULLEN. RAILWAY SIGNALING SYSTEM.

APPLICATION FILED JANA, 1904.

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INVENTOR 11.1% Z'huZZil/ WITNESSES A trurn e-n nrrnn s'ra rns Parana omen.

LOUIS H. THULLEN, OF EDGEVVOOD PARK. PENNSYLVANIA, ASSIGNOR TO THE UNION SIVITCH 8: SIGNAL COMPANY, OF SWISSVALE, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY SIGNALING SYSTEM...

Specification of Letters Patent.

Patented Dec. 25, 1906.

Application filed January 4, 1904. Serial No. 187,651.

ing by alternating currents on electric rail ways. In applying such a signaling system to electric railways one of the rails is made electrically continuousthat is, without portions thereof being insulated from each other. The other rails are divided into sections corresponding to what are known as blocksections, the adjacent ends of the rails of each section being insulated from each other.

By the present invention I employ both,

the continuous and the sectional railas a return-path for the car-propulsion current.

'Referring to the drawings, Figures 1 to 6 are dia rammatic views each showin a dif- D e n ferent form which my invention may assume.

Referrin now to Fi l A desi nates a direct-current generator furnishing current for the car-motor traveling along the railway. One terminal of the generator A is connected to the trolley-wire or third rail B and the other terminal to the track-rails, which form the return-path for the propulsion-current. The track, which comprises a con-' tinuous rail M and a rail N, is divided into block-sections F F F '&c., by providing insulation H at points in the rail N to 'form insulated sections. n n 72 &c., designate the insulated sections of the rail N Each blocl -section corresponds to the length of the sections into which .the railN is divided by the insulations At the entrance end of blocksections a railway signal C is provided, which signals govern the passage of trains into the block-sections. At I),I represent graphically a car bridging the rails M and N and provided with a trolley-pole or electric connector d, which contacts with the trolleywire B. E designates transformers having their primaries shown connected in series with an alternating-current generator L or other source of alternating-current supply and their secondaries 6 (except those at the endsv of the tracks) bridging the insulations IIthat is, the secondaries have one terof the adjacent rail-section.

- its danger position.

minal connected to one end of a rail-section and the other terminal to the adjacent end windings are composed of a few turns of copper bars and are of low ohmic resistance, approximately equal to the resistance of the rails, and furnish a path of low ohmic resistance for the car-pro u-lsion current from one rail-section to anot er. At each end of each block-section I referably place an inductive cross-bond which connects the ends of the rail-sections to the continuous rail. Each cross-bond comprises a coil 9 and furnishes a path of low resistance to neutralize the difference of potential in power-current between the track-rails caused by any difference in resistance that may exist in the trackrails. These inductive bonds also furnish paths for the alternating current generated by the transformers E E, &c.-that is, the bonds G at the adjacent ends of the block-sections F and F furnish a path for the alternating current sent from the correspondingly-located transformer Eand the bonds G at the adjacent ends of the blocksections F and F furnish paths for the alternating current from the correspondingly-located transformer E and so on with the other coils in the cross-bondings. In other words, each transformer E supplies alternating current to the ends of the blocksections adjacent which they are located. Relays K, responsive to the alternating signaling-current, are connected in multiple to the rails M and the sections of rail N. A relay is connected at each end of the section F and a relay at each end of the section F, and a relay K is connected at each end of the section F These relays may be of an of the well-known types which respond to a ternating current and are used in signaling systems of this type.

Where there is but one relay to a block the switch-arm 7: closes or connects the contacts 0 of the local circuit which controls the railway-signal for that block. The railway-signals may be of any type, but preferably of the semaphore type. N hen the local circuit of a railway-signal is closed, the semaphore thereof is held in its clear or safety position,

and when said circuit is open it is moved to When a train is on a block its wheels and axles shunt or short cir- The secondary cuit the relay or relays for that block, thereby causing the relay arm or arms k to move from the contacts 0, whereupon the railwaysignal displays a danger indication.

Where there are two or more relays to a block, the contacts 0 at each relay are all in.

series, and consequently when one set of the contacts 0 is opened the circuit which controls the railway-signal for that block is opened.

' The object of connecting a relay to both ends of a block-section is to have the currents which control the railway-signals go through both relays, so that if atrain should shunt the relays by being in the block to which the said relays are connected the signals will operate. If there should be a break in either rail between the two transformers at opposite ends of a block-section and a train should enter this block-section it would shunt one of the relays, but not the other; but as each relay controlsthe signal the-latter would operate. Any number of relays could be placed between the two end relays of a block-section. Also, if desired, a relay could be connected as the relay for block-section'F is shown connected. This relay which is at one end of the block-section F is shown connected by wires to the other end of said section, so that a train shunting the terminal of these wires where they are connected to the track will shunt the relay, even if one of the rails be broken between the points' to which the two sets ofconnections of the relays are made. Other branch Wires may similarly connect the relay to other selected points in the block-section, if desired, as shown in Fig.

3, in order to provide more points at which the relays may be shunted in case of breaks in the rails or of defective bonding or other break in the rail-circuits. I do not specifically claim this arrangement in this application, but do claim a relay that is operated by current from a plurality of points in the track-circuit.

' I I have placed'the primaries of the trans formers E, &c., in series with the generator L, so that a train entering a block-section and short-circuiting the secondaries will not injure the transformers by an excessive flow of current in the primaries and secondaries thereof. The primaries may be connected in parallel, however, as shown in Fig. 2, or in Fig. 4, where impedance-coils Z are inserted in the primaries to limit the flow of current when the secondaries are short-circuited by trains.

Referring to Fig. 2, the reference-letters are the same as on Fig.' 1 where the parts are the same. Each of the transformers E has its primary coil connected in multiple with the alternating-current generator L and its secondary coil in parallel with the continuous rail M and one of the rail-sections. i section to another.

1 alternating current set up by the trans ormer I provide transformers X, Whose primary coils each have one of their terminals con nected to the-end of one rail-section and the other terminal connected to the end of the adjacent rail-section, exce t that the terminal transformers, as the leftand one has its terminals bridged across the rails M and N. The windings of the primary coils of these transformers being composed of a few turns of heavy copper bar or cable afford low-resistance paths for the direct-current propulsion-' current from the direct enerator A, approximately equal to or less than the resistance of the rails. The secondaries Y of the transformers X are connected together in pairs, the members of each pair being in series. The

terminals of the pairs are connected to the trolley-wire B or any source ofdirect-current supply to the transformers at the points R and R,'which are at some distance from each other, so that there will be 'a'difierence of direct-current potential at the said points It and R, due to the resistance of the trollegwire B. This difference of potential will in proportion to the current traversing the through the medium. of the wire B, so that the alternating current generated in the secondary of one transformer will oppose the alternating current generated in the secondary of the other transformer. The inductive resistances V, placed between the oints R and R and one of the transformers prevent an excessive'flow of alternating current through the secondaries when the primary of one transformer X of a pair whose secondaries are in series is short-circuited. I have shown the secondaries connected in airs; but it is clear that three or more coul be connected. together in series between selected points It and R. The object of connecting the secondaries Y to the trolley-wire, feeder, or third rail B, as described, is to neutralize the magnetism of the core caused by the direct current which passes from the rail N through the primaries. The difference of direct-current potential at the connecting-points R and R is in proportion to the current traversing the rails and the primaries of the transformers. The number of turns in the secondaries and the direction of the direct current in them are so connected and proportioned as to approximately eliminate the magnetism of the core due to the direct current in the primaries. As the transformers X are between the ends of the sections of the rail N, the counter electromotive force set up in the transformer will keep anylarge amount of. alternating current Hence, for exam 1e, an

' current.

case demands, their purpose being the same as in Fig. 1. The relays K are connected the same as in Fig; 1, two relays being used for block F and one each for blocks F and F; but any number of relays to a block may be used. The transformers E are shown connected one at one end of each block and furnishing alternating current for that block. Aresistance P, either inductive or non-inductive, is connected in series with the secondary of each transformer, if the transformers are connected in multiple, as shown, in order-to limit the flow of alternati current through the secondary when it is s horbcircuited by the trains. 1f the transformers be connected in series, as in Fig. 1, these resistances will not be needed, as explained under the description of said figure. I do not limit myself to the inserting of resistance between the secondary and the track, as it is well known that a transformer can be used with a largeleakage' factor, the secondary of which can be shortcircuited without abnormal flow of current in the primaryj Referring now to Fig. 3, the transformers E have, as in'Fig. 1, their secondaries e con-- nected between the ends of the insulated rail-sections and their primaries a connected in series with the source L of alternating The secondary coils being com-* posed of heavy copper bar or cable have but few turns and afford paths of low resistance for the return-current to the generator A, and besides supply current to the block-sections. The primaries a could be connected in multiple, as in Fig. 2 or Fig. 4, by inserting the resistance P or Z to limit the flow of alternating current when trains short-circuit the sec ondaries e. The transformers E are provided with additional coils e connectedin series with the direct-current, generator U,

whose field-winding u is connected to the rails M andN, and therefore traversed by the direct current, which traverses the secondaries e from the enerator A. Therefore the current generated by the dynamo U and traversing the coils e is in a definite proportion to the current in the field-winding u of the dynamo U and in the rail-sections bridged by the coils. The windings of the coils e are such thatthe current generated in one will oppose the current generated in the one next to it. The turns of the coils and the direction of direct current in the windings e of the transformers E are such as to approximately neutralize the magnetism of the core caused by the direct current traversing the windings e. The cross-bondings G are used as in F ig- 1, and the block-section F is shown with one relay and the section F with two relays, connected as in Fig. 1, except that the single relay of the section F has connection with the, rails at three points instead of at two points, as shown for the block-section F of Fig. 1. The number of connections will be sufficient for the conditions of each particular block, the plural connection being provided, as before explained, to cause the signals C of a block to be actuated if a break or its equivalent should occur in a rail between the train and the relay of the block on which the train is running.

ReferringtonFig. 4, the dynamo A, the cross-bondings G, the signals 0, the relays K, and the secondary windings e of the transformers E are the same as in Fig. 3. The primary windings e of the transformers are shown in Fig. 4 in multiple .with the mains of the source L of alternating current, impe dance or resistance coils Z being interposed between each winding e and the main to whichitis'connected to prevent excessive current in the transformers when the secondaries e are short-circuited by trains. The windings e of the transformers E are connected together in pairs and joinedto the trolley wire,.feeder, or third rail B, the same as the coils Y in Fig. 2. The pairs of windin s e are connected to the wire, feeder, or rail B to the points R and R, which are at some distance from each other, so that there will be a difl'erence of potential between the terminals R and R, due to the resistance of the, trolley wire, feeder, or third rail D.v The difference of potential causes a current to flow in the coils e in proportion to the current fiowin through therails and the secondaries e of the transformers E. The number of turns, the direction, and amount of the direct current flowing through thecoils e are such as to neutralize the magnetism of the cores of the transformers caused by the direct current traversing the secondaries e.

On Fig. 5 the parts are the same as on Fig. i

2, except that the coils X, which correspond to the coils X of Fig. 2, are not connected between the ends'of adjacent rail-sections, as in Fig. 2, but are bridged across the continuous rail M and the ends of the sections of the rail N. The pairs of connected coils X each have one terminal connected to the rail M, and one of the coils X has its second terminal connected to the end of'one rail-section, and the other ofthe coils has its second terminal connected to the adjacent end of the adjacent rail-section. The coils Y are connected up proportion of parts the coils their connections apply equallywell to the .coil X and Y of Fig. 5. I

to the system the same as on Fig. 2. All the description of Fi 2. as to girposes and and Y and I do not desire to limit myself to the connecting together of two secondaries Y of the transformers X, as three, four, or more secondaries could be connected together.

In Fig. 6 the direct-current dynamo A, the feeder wire or third rail B, the rails M and, N, the signals C, and relays Khave the same characteristics and are connected up the same as on the other figures, The transformers E ,&c., arearrangedin pairs. A pair of secondaries e are located at the junctions of the block-sections, one'terminal of each pair being connected to the rail M. The

Y second terminal of one ofthe pairs is con nected to the end of one rail-section and the second terminal of the other one of the pair is connected to the adjacent end of the adjacent rail-section. The primaries e are connected in series with the source L of alternating current. A secondary Winding Y is provided for each member of each pair of transformers, and the secondaries of each pair are connected in series, their terminals bein connected to-the Wire or third rail B at R and R, which are some distance a art, so that there will exist a difference of irect-curren't potential between them due ,to the resistance of the Wire or third rail B The windings of the transformer-coils are such that the direct current in the coils a will neutralize the magnetism of the cores caused by the directcurrent inthe coils e. Of course any number ofseco ndaries Y could be connected to ether.

n Fig. 6 I have shown the'car D on blocksection F. The alternator L through the transformers E connected to op osite ends of the section F, normally supp ies current to cause the rela s K to maintain their switch-arms k bri ging the pairs of contacts 0 ofthe si nal C. So long as the arms is .maintain t e local circuit of the signal C closed the signal will indicate a clear track, as shown by the signals C at block F The car Don the block F short-circuits the relays, which being deprived of the normal flow of alternating current opens the local circuits at the contacts 0, whereupon the signal C dis-' pla s danger, as shown.

t is to be understood that each of the relays K in all the figures is only operable by alternating currents.

It will be seen that in each variety of my invention both the continuous and the sectional rails constitute a return for the direct propulsion-current and that the alternating current furnished to each block-section cannot pass to adjacent sections with sufiicient strength to control the signals thereof,

I do not limit myself to the precise combition may be the same or diflerent in all or any number of sections. I do not limit myself in other particulars shown, as many changes may be made which will readily occur to thoseacquainted with the art to which my invention relates.

Though I have called the element B I a --trolley-wire, it may as well be a feeder Wire or third rail. i

Though I have shown on Figs. 5 and 6 a leg of each pair of transformers connected to the continuous rail, the two said legs of each pair of transformers would referabl in practice be directly joined together and ave a single or common connection with said rail.

What I claim as my invention is- 1. In combination with an electric railway,

carropulsion current and 'is divided into bloc -'sections' by insulation, a power-generator for the car-propulsion current, inductive bonds for conducting the power-current around insulation-points and providedwith means for preventing saturation of their cores bythe pro ulsion-current, and a signaling system for t e railway comprising a railway-signal for each block-section, a trackcircuit for each block-section, an alternatin signaling-current for each block section, an a relay for each block-section which responds to the alternating current of its block-section to control a railway-signal as to one of its opf erations.

2. In combination with a railway the trackwa of which is divided b insulations to form lock-sections and whic is included in the return-circuit for the car-propulsion current, a generator for the car-pro ulsion current, a conductor connected with t e rails arpund insulation-points and traversed by 'ductor, a second conductor for said core also traversed by the propulsion-current to revent saturation of the core by the propulsioncurrent flowing through the first conductor, and a signaling system for the block sections COIIIPIlSlII track-circuits, relays and railway-signa scontrolled by the relays.

3. In combination with a railway the trackwa of which is divided b insulations to form lock-sections and whic is included in the return-circuit for the car-propulsion current, a generator for the car-propulsion current, a conductor connected with the rails around insulation-points, and traversed by the propulsion-current, a core for said conductor, a second conductor for said core also traversed by the propulsion-current to revent saturation of the core by the ropulslon-current flowing through the st conductor, cross-bonds for the trackway, and a signaling system for the block-sections comprising track-circuits, relays and railway-signals controlled by the relays.

nation shown, as" the apparatus of each sec-- the propulsion-current, a core for said conthe trackway of which forms a return for the i 4. In combination with a railway the] dance-windings, the windings being such track-rails of which are divided to form block-sections by insulations placed in one of its running rails and both of which are i11- cluded in the return-circuit for the car-propulsion current, a generator for the car-propulsion current, a conductor connecting two adjacent block-rails, a core for said conductor, a second winding surrounding said core and traversed by the car-propulsion current to prevent saturation of the core, and asignaling system for the block-sections of the railway comprising track-circuits, relays and railway-signals controlled by the relays.

5. In combination with a railway the track-rails of which are divided to form block-sections by insulations placed in one of its running rails and both of which are included in the returncircuit for the car-propulsioncurrent, a generator for the car-propulsion current, a conductor connecting two adjacent block-rails, a core for said conductor, a second winding surrounding said core and traversed by the car-propulsion current to prevent saturation of the core cross-bonds for the track-rails, and a signaling system for the block-sections of the railway comprising track-circuits, relays and railwaysignals controlled by the relays.

6. In an electric railway signaling system employing a closed signal-controlling trackcircuit, a plurality of block-sections, one rail being divided into insulated sections corresponding to the block-sections, a signal for each block-section, and a plurality of relays controlling one or more of the signals, the relays associated with any section being connected at a plurality of points with the section controlled by the signal.

7. In an electric railway signaling system, they combination of a closed track-circuit, a source of alternating currentfor said trackcircuit, a plurality of blocksections, one of the rails being divided into sections corresponding to the block-sections, a signal for each section operable by said current, an in ductive impedance-winding in a connection between adjacent rail-sections, and a supplementary winding connected to a source of direct current, and associated with said impedance-winding whereby the core magnetization caused by the direct propulsion-current traversing the impedance-winding in passing from one ra1lsect1on to another 1S neutralized.

8. In an electric railway signaling system, the combination of a closed track-circuit, a source of alternating current for said trackcircuit, a plurality of block-sections, one of the rails being divided into sections corres onding to the block-sections, a signal for eac 1 section operable bysaid current, aplurality of inductive impedance-windings in a connection between adjacent rail-sections, and a sup lementary winding connected to a source 0 ,direct current and associated with said impethat the alternating currents induced in the supplementary winding of connected impedance-windings will neutralize each-other.

9. In an electric railway signaling system, the combination of closed track-circuits, a source of alternating current for each trackcircuit, a plurality of block-sections, one of the rails being divided into sections corresponding to the block-sections, a signal for each section operable by said current, an inductive impedance-winding in connection between adjacent rail-sections, a supplementary winding connected to a feeder wire or rail for the car-motor, and associated with said impedance-winding whereby the core magnetization caused by the direct propul. sion-current traversing the impedance-winding in passing from one rail-section to another, is neutralized, and a source of directcurrent supply for said feeder wire or rail.

10. In an electric railway signaling sys tem', the combination of closed track-circu1ts, a source of alternating current for each trackcircuit, a luralit r of block-sections, one of the rails )eing divided into sections COI'I'B, sponding to the block-sections, a signal for each section operable by said current, a path of high impedance to the alternating current from one rail-section to an adjacent rail-section, and a source of direct current associated with said impedance to neutralize the action therein of the direct propulsion-current derived from the track.

11. In an electric railway signaling system, the combination of closed track-circuits, a source of alternating current for each trackcircuit, a plurality of block-sections, one of the rails being divided into sections corresponding to the block-sections, a signal for each section operable by said current, a path -of high impedance to the alternating current from one rail-section to an adjacent rail-section, and a source of direct current associated with said impedance to neutralize the action therein of the direct propulsion-current derived from the track, said source having a definite ratio to the said current derived from the track.

12. In an electric railway signaling system, the combination of closed track-circuits, a source of alternating current for each trackcircuit, a pluralit of'block-sections, one of the rails being divided into sections corresponding to the block-sections, a signal for each section operable by said current, a path of high impedance to the alternating current, from one rail-section to an adjacent rail-section, and a source of direct current associated with said im edance to neutralize the action therein of t 1e direct pro ulsioncurrent derived from the track, sai source being variable so as to maintain a definite ratio to the said current derived from the track.

v 13. In an electric railway signaling system, the combination of closed track-circuits, a source of alternatin current for each trackcircuit, a plurality'o block-sections, one of the rails being divided into sections corresponding to the block-sections, a signal for each section operable by said current, a path of high impedance to the alternating current from one rail-section to an adjacent railsection, and a supplemental source of direct current associated with said impedance to neutralize the action therein of the direct pro ulsion-current derived from the track, sai supplemental source of current being governed by the return direct propulsioncurrent on the track.

14. In an electric railway signaling system, the combination of closed track-circuits,

a source of alternating current for each track-- circuit, a plurality of block-sections, one of the rails being divided into sections corresponding tothe block-sections, a signal for each section 0 erabl'e by said current, and

means for insu ating the alternating current in one rail-section from the adjacent railsection, an inductive cross-bonding connecting the rails and having a low resistance to direct current, and a high impedance to the alternating signal-current, and a winding associated with the cross-bonding to neutralize the magnetization of the core thereof caused by the return propulsion current on the track.

15. In an electric railway signaling system employing closed signal controlling track-circuits, a plurality of block-sections, one rail being divided into insulated sections corresponding to the block-sections, a signal for-each block-section, a relay controlling the signal and operative by current from a plurality of points in the track-circuit of the block-section for which the signal is provided Signed at Pittsburg this 24th day of De cember, 1903.

LOUIS H. THULLEN. Witnesses:

ALICE E. DUFF, F. M. BARBER. 

